Digispark is an Attiny85 based microcontroller development board similar to the Arduino line which is smaller and cheaper. Now you can connect an infrared detector to the Digispark and turn it to an infrared controller to control your devices.

Digispark is copyrighted by Digistump LLC (digistump.com) and the full license is here:

Digispark is an ATtiny85 based microcontroller development board come with USB interface. Digispark is very small and inexpensive but less powerful than Arduino. Coding is similar to Arduino, and it use the familiar Arduino IDE for development.

Digispark is copyrighted by Digistump LLC (digistump.com) and the full license is here:

Here is an article on how to making a Digispark, however if you want to purchase a finished product, you can always get it from Digispark's author homepage.

This example demonstrates how to use a 4x4 matrix keypad access password from an Arduino. Sketch below required to install password and keypad library, both available at Arduino Playground. Below list the functions of password library:

Among the RFID modules, Stronglink SL018 is the lowest cost RFID module that I can get which supports read and write. SL018 is a 13.56MHz RFID module, it supports Mifare 1K, Mifare 4K and Mifare Ultralight. The specification are as follow: